Fred is a more streetwise footballer, sharper mind in tight spaces, better first touch.
McT is a better athlete, better goalscorer, better defending aerial set pieces and still has some room to mature.
They are both so important when we play away to Man City or Liverpool and need dynamic, courageous bulldogs snapping at heels. When we're home to a team parking the bus then they often don't have enough creativity, especially if Bruno has 2 men on him always to null our main threat. But in most PL games they are good enough despite limitations.
I'd imagine Ole will spend 10 or 20 million on some wonderkid central midfielder in the summer, along with giving VDB a bigger role next season, to push McT and Fred for a first XI spot. I just hope we never ever see Pogba and Matic in a midfield 2 ever again. It's so costly.